This invention relates generally to rail yards, and more particularly to determining the location of rolling stock, including railcars and locomotives, within a rail yard.
Rail yards are the hubs of railroad transportation systems. Therefore, rail yards perform many services, for example, freight origination, interchange and termination, locomotive storage and maintenance, assembly and inspection of new trains, servicing of trains running through the facility, inspection and maintenance of railcars, and railcar storage. The various services in a rail yard compete for resources such as personnel, equipment, and space in various facilities so that managing the entire rail yard efficiently is a complex operation.
The railroads in general recognize that yard management tasks would benefit from the use of management tools based on optimization principles. Such tools use a current yard status and a list of tasks to be accomplished to determine an optimum order in which to accomplish these tasks.
However, any management system relies on credible and timely data concerning the present state of the system under management. In most rail yards, the current data entry technology is a mixture of manual and automated methods. For example, automated equipment identification (AEI) readers and AEI computers determine the location of rolling stock at points in the sequence of operations, but in general, this information limits knowledge of rolling stock whereabouts to at most, the moment at which the rolling stock arrived, the moment at which the rolling stock passes the AEI reader. and the moment at which the rolling stock departs.
The location of assets within a rail yard is typically reported using voice radio communications. Point detection approaches such as wheel counters, track circuits, and automatic equipment identification (AEI) tag readers have been used to detect assets at specific, discrete locations on the tracks. Modern remote control systems use GPS and AEI tags to prevent the remote-controlled locomotive from traveling outside the yard limits. Cameras have been deployed throughout rail yards with shared displays to allow rail yard personnel (i.e. yard masters, hump masters, manager of terminal operations) to locate engines and other assets. However, none of these approaches provide a continuous, real-time view as to the location of all rail yard assets of interest.
It is desirable to know where assets are located within a rail yard in real time (e.g., within the last 10 seconds). These assets could be humans (i.e. car inspectors), maintenance of way vehicles, or locomotives for example. For locomotives it is desirable to know what track they are on and at what position on that track they are located.
Most rail yards do not have accurate track location data. Adjacent tracks can be 13.25 feet apart (according to Association of American Railroads Plate C standard) and track location information may not exist, or may be accurate only to several feet. Collection of this track location information using conventional survey methods and techniques can be time consuming, costly, and negatively impact railroad freight operations.
Accordingly, it is desirable to provide a method and apparatus for providing a continuous real-time view of the location of all the rail yard assets of interest and the rail yard processing task they are associated with.